共查询到20条相似文献,搜索用时 0 毫秒
1.
G. González Hernández A. Hardisson de La Torre J. J. Arias León 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1996,203(6):517-521
This study determines ash, K, Ca, Na, Mg, Fe, Cu, Pb, and Zn content in musts and wines of the DOC Tacoronte-Acentejo (Tenerife, Canary Islands) from two consecutive harvests. Samples were treated with HNO3 and H2O2. Na and K were determined by flame photometry and the remaining metals by air/acetilene flame atomic absorption spectrophotometry. Significant differences were observed in Na, Ca and Mg contents between both harvests, possibly due to climate conditions. 相似文献
2.
微波消解-电感耦合等离子体发射光谱法测定大米中铜、锰、铁、锌、钙、镁、钾、钠8 种元素 总被引:2,自引:0,他引:2
建立微波消解-电感耦合等离子体发射光谱法测定大米中铜、锰、铁、锌、钙、镁、钾、钠8 种元素的方法。样品经微波消解后,直接用电感耦合等离子体-发射光谱仪同时测定上述8 种元素。结果表明:此方法的检出限在0.9~12 μg/L之间,线性相关系数r≥0.999 65;加标回收率在96.7%~104.3%之间,相对标准偏差<5.0%;对小麦标准物进行测定,结果令人满意。 相似文献
3.
Maribel Valdez-Morales Kathleen Barry George C. Fahey Jr. Jorge Domínguez Elvira Gonzalez de Mejia María Elena Valverde Octavio Paredes-López 《Food chemistry》2010
Huitlacoche galls were produced in 15 creole maize genotypes harvested at two stages of development, 23 and 28 days after inoculation, and in a hybrid genotype harvested at six stages of development. Raw and cooked galls were evaluated for proximate constituents, carbohydrate composition and antimutagenic activity. Huitlacoche grown in creole maize exhibited differences in concentrations of some of the proximate and carbohydrate components, due to genotype and stage of development; some effects were also observed in hybrid maize, as a result of stage of development and cooking. Huitlacoche has a considerable amount of crude protein (9.8% average in creole maizes, and 11.3% in hybrid maize). Most of the values for total dietary fibre, β-glucans, and total free sugars were higher than those reported for other edible mushrooms. The high concentration of antimutagenic substances appears to be an asset of this culinary delicacy. 相似文献
4.
Kelber Miranda Alan Lima Vieira Marcos André Bechlin Felipe Manfroi Fortunato Alex Virgilio Edilene Cristina Ferreira José Anchieta Gomes Neto 《Food Analytical Methods》2016,9(7):1887-1894
Establishing fast, simple, low-cost, and efficient sample preparation procedures to determine elements in foodstuffs is a relevant aspect for nutritional and health purposes. For this reason, the recently proposed closed-vessel conductively heated digestion system (CHDS) was evaluated for the digestion of milk powder, chocolate powder, and soluble coffee samples aiming for Ca, Cu, Fe, K, Mg, Mn, Na, and Zn determinations by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) and Cd, Mo, and Se determinations by inductively coupled plasma mass spectrometry with tandem configuration (ICP-MS/MS). The accuracy was evaluated by analyzing two milk certified reference materials digested by the CHDS and a microwave oven for comparison. When using the CHDS, recoveries for the analytes varied from 91 to 104 %. For microwave digestions, recoveries within the 94–109 % intervals were obtained. The method was then applied to the samples. For comparative purposes, the analytes were also determined in the samples after microwave digestion, and the results between the two digestion systems showed no differences based on a paired t test at a 95 % confidence level. Similar analytical blanks were obtained because quartz digestion tubes were used in both digestion systems. The CHDS with quartz tubes is an interesting alternative for laboratories dedicated to large-scale routine analysis because volatile elements usually found in very low concentrations in food samples such as Cd and Se can also be determined. 相似文献
5.
Tanmoy Karak Funso Raphael Kutu Jyoti Rani Nath Indira Sonar Ranjit Kumar Paul Romesh Kumar Boruah 《Critical reviews in food science and nutrition》2017,57(14):2996-3034
Tea (Camellia sinensis L.) is a perennial acidophilic crop, and known to be a nonalcoholic stimulating beverage that is most widely consumed after water. The aim of this review paper is to provide a detailed documentation of selected micronutrient contents, viz. boron (B), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn) in made tea and tea infusion. Available data from the literature were used to calculate human health aspect associated with the consumption of tea infusion. A wide range of micronutrients reported in both made tea and tea infusion could be the major sources of micronutrients for human. The content of B, Co, Cu, Fe, Mn, Mo, and Zn in made tea are ranged from 3.04 to 58.44 μg g?1, below detectable limit (BDL) to 122.4 μg g?1, BDL to 602 μg g?1, 0.275 to 13,040 μg g?1, 0.004 to 15,866 μg g?1, 0.04 to 570.80 μg g?1 and 0.01 to 1120 μg g?1, respectively. Only 3.2 μg L?1 to 7.25 mg L?1, 0.01 μg L?1 to 7 mg L?1, 3.80 μg L?1 to 6.13 mg L?1, 135.59 μg L?1 ?11.05 mg L?1, 0.05 μg L?1 to 1980.34 mg L?1, 0.012 to 3.78 μg L?1, and 1.12 μg L?1 to 2.32 μg L?1 of B, Co, Cu, Fe, Mn, Mo, and Zn, respectively, are found in tea infusion which are lower than the prescribed limit of micronutrients in drinking water by World Health Organization. Furthermore, micronutrient contents in tea infusion depend on infusion procedure as well as on the instrument used for analysis. The proportion of micronutrients found in different tea types are 1.0–88.9% for B, 10–60% for Co, 2.0–97.8% for Cu, 67.8–89.9% for Fe, 71.0–87.4% for Mn, 13.3–34% for Mo, and 34.9–83% for Zn. From the results, it can also be concluded that consumption of three cups of tea infusion per day does not have any adverse effect on human health with respect to the referred micronutrients rather got beneficial effects to human. 相似文献
6.
《Food chemistry》1999,67(2):113-121
The present in vitro study on starchy legumes and their Mg bioavailability, covers the factors: cooking, dietary fibre, phytic acid and the competitive binding of other minerals. Mg-binding capacity of food legumes (butter beans, broad beans and lentils) in the raw, cooked and fibre-rich fraction (FRF) forms with Mg addition alone and with Ca, Fe, Zn and Cu (at concentrations based on the recommended daily allowance) was investigated in conditions simulating the small intestine. The three legumes in the raw and cooked forms showed more significant (P<0.01) Mg-binding when Mg was added with Ca, Fe, Zn and Cu than with Mg addition alone. The FRFs were found to bind significantly (P<0.01) more Mg than the raw and cooked forms. Cooking significantly decreased (P<0.01) the Mg-binding capacity of raw butter beans, broad beans and lentils at separate Mg addition or with Ca, Fe, Zn and Cu. 相似文献
7.
Tomato plants were grown in a calcareous soil supplemented with two organic wastes (sewage sludge and epicarp-mesocarp of the almond tree fruit). They were irrigated at three levels of salinity caused by the addition of sodium chloride. N, P, K, Na, Ca and Mg were determined in the soil and tomato fruits. The treatments had a significant incidence on mineral content in fruit and soil. 相似文献
8.
9.
Uwe Harms 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1975,157(3):125-132
Zusammenfassung Mit dem Ziele, unsere Kenntnisse über den gegenwärtigen Grad der Schwermetallspeicherung in Fischen zu erweitern, wurde der Gehalt an den metallischen Spurenelementen Mangan, Eisen, Kobalt, Nickel, Kupfer, Zink, Cadmium, Blei und Quecksilber in bestimmten Fischarten (Kabeljau und Scholle) aus küstennahen und küstenfernen Fanggebieten der Deutschen Bucht bestimmt. Als Meßverfahren wurde die Atom-Absorptions-Spektrophotometrie eingesetzt: Bei der Bestimmung der Elemente Mn, Fe, Cu und Zn wurde die herkömmliche Flammentechnik (Laminarbrenner, Luft-Acetylen-Flamme) verwendet. Die flammenlose Atom-Absorptions-Spektrophotometrie unter Verwendung der Graphitrohrküvette diente der Bestimmung von Cd, Pb, Co und Ni. Der Gehalt an Gesamt-Quecksilber wurde mit der sogenannten Kaltdampf-Methode ermittelt. Zur Vermeidung von Fehlinterpretationen der Meßwerte von Kobalt und Nickel, die sich insbesondere bei diesen Elementen als Folge von Matrixeffekten ergeben, wurde eine spezielle Aufarbeitungstechnik entwickelt, die auf einer selektiven Abtrennung und Anreicherung durch Chelataustauscher-Chromatographie über Chelex 100 beruht.Die ermittelten analytischen Daten werden in einem Diagramm mit doppelt logarithmischem Maßstab dargestellt. Auf der Abscisse ist der Gehalt (Mittelwert von Mehrfachbestimmungen) aufgetragen, auf der Ordinate die zugehörige Reproduzierbarkeit (als Variationskoeffizient) des jeweiligen Meßverfahrens. Allen untersuchten Elementen lassen sich gut umrissene Gehaltsbereiche zuordnen.Das Spektrum der Gehalte an den Übergangsmetallen Mangan, Eisen, Kobalt, Nickel, Kupfer und Zink zeigt bei einem Vergleich von Fischen gleicher Art, aber verschiedener Herkunft nur geringe Unterschiede. Ebenso entsprechen einander die Gehalte, welche an Hand der Untersuchungen verschiedener Fischarten (Kabeljau, Scholle) gleicher Herkunft gewonnen wurden. Die ermittelten Werte für Cadmium, Blei und Quecksilber lassen erkennen, daß Schollen, die sich in der unmittelbaren Küstenzone aufhalten, erhöhte Gehalte aufweisen.
The levels of heavy metals (Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Hg) in fish from onshore and offshore waters of the German Bight
Summary With the intention of increasing our knowledge about the actual degree of heavy metal accumulation in fish, the contents of the elements manganese, iron, cobalt, nickel, copper, zinc, cadmium, lead and mercury in certain fish species (cod and plaice) from onshore and offshore waters of the German Bight have been determined. The measurements have been performed by atomic absorption spectrophotometry: Flame AAS was used as investigating procedure for the determination of Mn, Fe, Cu and Zn. A non-flame atomization system with a heated graphite tube was used for the determination of Cd, Pb, Co, and Ni. The concentration of total Hg was estimated according to the so-called cold vapour atomic absorption method. In order to avoid errors in interpretation of measured values of Co and Ni, which occured as a result of matrix effects, a special technique has been developed. This based upon an selective separation and enrichment by chelate exchanger chromatography (Chelex 100).The analytical data obtained are plotted in a diagram with log.-log. scale. The content is shown on thex-axis, and the corresponding relative reproducibility (variation coefficient) of the method used is shown on the y-axis. For all elements investigated certain levels have been found out.From an examination of the results it appeared that there were comparatively small differences in the prevailing concentrations of transition metals Mn, Fe, Co, Ni, Cu, and Zn between samples of the same species from different areas. Likewise, the levels estimated for plaice did not differ from those estimated for cod. There is some evidence of elevated levels of Cd, Pb, and Hg in plaice from areas along the coastline.相似文献
10.
ICP-MS analysis of a series of metals (Namely: Mg,Cr, Co,Ni, Fe,Cu, Zn,Sn, Cd and Pb) in black and green olive samples from Bursa,Turkey 总被引:1,自引:0,他引:1
Ninety-two black and green table olive samples from the Bursa, Turkey were analyzed. The olives were sampled from 56 brands, four processing methods and three packing types. The concentration of Mg, Cr, Co, Ni, Fe, Cu, Zn, Sn, Cd and Pb were measured by inductively coupled plasma mass spectrometry (ICP-MS). While the most concentrated element was Mg (125.11 ± 5.02), Co (0.09 ± 0.01) had the lowest concentration in tested olive samples. The levels of the ten metals studied are within safe limits. The data here obtained will be valuable in complementing available food composition data, and estimating dietary intakes of heavy metals in Turkey. The metals Mg, Fe, Zn, Sn and Pb presented significant differences (p < 0.05) in content between two types, hence processing method, brand and packing material must influence their content. 相似文献
11.
I. González-Martín J.M. Hernández-Hierro I. Revilla A. Vivar-Quintana I. Lobos Ortega 《Food chemistry》2011
The results of this work show that it is possible to rapidly quantify calcium, phosphorus, magnesium, potassium and sodium in unknown cheeses elaborated with percentages (0–100%) of milk from different species (cow, ewe, goat) by direct application of the fibre-optic probe on the sample without previous destruction or treatment of the sample. Of the total number of samples, 170 were used to develop the calibration models using the Modified Partial Least Squares (MPLS) regression method and 57 samples were used for external validation. The multiple correlation coefficients (RSQ) and prediction corrected standard errors (SEP (C)) obtained for calcium (0.74, 0.64), phosphorus (0.69, 0.29), potassium (0.86, 0.13), and sodium (0.92, 0.71) in g/kg respectively and magnesium (0.72, 30.9) in ppm, indicated that the models developed allow the determination of Ca, P, K, Na and Mg in unknown samples of cheeses of varying compositions up to 6 months of ripening. 相似文献
12.
The effects of sample preparation, cultivar, leaf age and tea processing on melatonin content of mulberry (Morus spp.) leaves were investigated. Sample preparation using ultrasonic technique in combination with solid phase extraction resulted in high recovery rate (76%), when compared to homogenisation in combination with liquid–liquid extraction procedure (12% recovery rate). The melatonin contents in mulberry leaves harvested from three major cultivars (Buriram 60, Sakonnakhon and Khunphai) grown in Thailand were identified and quantified using high-performance liquid chromatography combined with fluorescence detector. The average melatonin content of the mulberry leaves cv. Buriram 60 (279.6 ng/g dry weight (DW)) was higher than those of cv. Sakonnakhon (100.5 ng/g DW) and cv. Khunphai (40.7 ng/g DW). The melatonin contents of all cultivars tested were highest in the tip of the leaves, followed by that in the young leaves, whereas the lowest was found in the old leaves. The melatonin contents of the two types of tea produced from mulberry leaves cv. Buriram 60 were also determined. Heat treatment during tea processing decreased the melatonin content in mulberry leaves cv. Buriram 60 by approximately 87%, when compared to that of the fresh leaves. However, there were no significant differences between the melatonin contents of the mulberry leaf tea produced with blanching (mulberry green tea) and those produced without blanching (mulberry black tea). 相似文献
13.
Evans Adei Kwadwo Forson-Adaboh 《Food Additives and Contaminants: Part B: Surveillance Communications》2013,6(2):100-105
Accumulation of toxic metals in liver, a rich natural source of essential elements, can present health risks to regular consumers of liver. A total of 35 fresh liver samples of cow, sheep, goat, pig, grass-cutter (Thryonomys swinderianus), gaint rat (Cricetomys gambianus), red deer (Cervus elaphus), chicken and antelope (Antilocapra americana) were obtained from three different markets in Accra and Kumasi, Ghana. Samples were analyzed using atomic absorption spectrometry and an automatic mercury analyzer. Levels of iron in the grass-cutter and pig of 500.5–645.4 mg kg?1 were the highest in the animal livers examined. Mn concentrations were highest in grass-cutter and rat liver, ranging 16.5–30.2 mg kg?1. The safe Cu and Zn permissible limits of 20 and 50 mg kg?1 were exceeded in 70 and 75% of the liver samples, respectively. Generally, for each animal group studied, at least 50% of the sample livers exceeded the Cd permissible limit of 0.5 mg kg?1. The levels of Pb, which ranged 1.3–13.8 mg kg?1, exceeded the proposed European Commission (EC) limit of 0.5 mg kg?1. Care must be taken by regular consumers of the iron-rich animal livers of grass-cutter, pig and rat because they also had the highest levels of Pb (in grass-cutter and pig) and Cd (in grass-cutter, rat and pig). The liver samples analyzed for Hg had values far below the permissible limit of 0.5 mg kg?1. 相似文献
14.
William P McCarthy Karen Daly Anna Fenelon Christine O'Connor Noel A McCarthy Sean A Hogan John T Tobin Tom F O'Callaghan 《International Journal of Dairy Technology》2020,73(2):459-467
Milk and dairy products are comprised of a complex matrix of components that can interfere with analysis and, as a result, are often not suitable for direct introduction into analytical instruments. Energy‐dispersive X‐ray fluorescence spectrometry (EDXRF) can bypass time‐consuming preparation steps, with potential for rapid, onsite analysis of minerals. In this study, five major milk minerals, sodium, magnesium, potassium, phosphorus and calcium, were quantified in dairy powders, using EDXRF, and the systemic bias of the method was evaluated by Bland–Altman analysis. No significant systemic bias was observed for the quantification of sodium, magnesium, potassium and phosphorus, meaning that EDXRF has potential to be used as a rapid offline analytical technology suitable for the analysis of these minerals in skim milk powders. 相似文献
15.
An inductively coupled plasma mass spectrometry method was established for direct determination of some (ultra)trace elements in salt samples applying aerosol dilution approach. As the method does not require any sample pretreatment, contamination risk was very low, and analytical features were excellent. The method detection limits were 12, 6, 18, 2, 34, 68, and 87 ng/l for Cr, Mn, Fe, Co, Ni, Cu, and Zn, respectively. The combinatorial use of collision/reaction cell, and kinetic energy discrimination was found to be very effective to eliminate polyatomic interferences. The accuracy of the method was validated by the analysis of certified reference materials, CWW-TMG waste water and SEM-2011 water sample in high-salt matrix, 0.5 % (w/v) NaCl solution. The relative standard deviations were lower than 11 % for all elements without any sample pretreatment. The spike recovery values were 96–101 % at 0.2 and 1.0 μg/l, showing the applicability of the presented method for direct (ultra)trace analysis of edible salt samples. 相似文献
16.
The aim of this study was to determine the effects of extraction temperature on the colour as well as on the phenolic and parthenolide content of feverfew (Tanacetum parthenium) aqueous extracts, with a view to incorporating the extracts into a beverage. Results showed that extraction temperatures of 20–70 °C yielded dark-coloured extracts with low total phenol and a relatively high total tannin concentration. However, increasing the temperature to 75 °C produced lighter-coloured extracts with a significantly higher concentration of total phenols, lower total tannin fraction and maximum extraction of parthenolide. Higher extraction temperatures (80–100 °C) yielded suitably pale extracts rich in total phenols, but with progressively higher total tannin to non-tannin ratio and lower parthenolide content. The compromise temperature of 80 °C was found to provide extracts rich in parthenolide content, phenolic content and with a desirable colour, suitable for incorporation into a functional beverage. 相似文献
17.
The external egg morphology of two stored-product pests, Stegobium paniceum and Lasioderma serricorne, is presented herein based on optical and scanning electron microscope micrographs. The diagnostic characteristics of the eggs of the pests, including the presence or absence of a micropyle, are described and discussed. Overall, several notable differences were observed between the eggs of these species in regard to their shape, size and surface structures. 相似文献
18.
Water-soluble feruloyl arabinoxylans (feraxans), isolated from native and malted (96 h) rice (Oryza sativa) and ragi (Eleusine coracana) grains, were fractionated on DEAE-cellulose, followed by purification on Sephacryl S-300 and the homogeneity was ascertained by high performance size exclusion chromatography, cellulose acetate and capillary electrophoresis. Structural characterization of the purified polysaccharides by methylation, followed by GLC–MS, and also by 1H NMR and 13C NMR spectroscopy, indicated very high branching and presence of high amounts of O-2 substituted xylans. The amount of O-2, 3 disubstituted xylopyranosyl residues and the arabinose:xylose ratio was higher in malt feraxans. All feraxan samples consumed almost equal amounts of periodate (4.02–4.30 μmol/mg). High amount of xylose (∼40%), as identified by Smith degradation, further substantiated the high branching of feraxans. A model is presented depicting the structure of water-soluble feraxans from rice and ragi and their changes upon malting. 相似文献
19.
This study showed the relationship between tea leaf age, bud and first two leaves, and shade levels, on the relative concentrations of six major compounds of tea leaf, namely l-theanine, caffeine, and the major tea catechins; (−)-epigallocatechin gallate (EGCG), (−)-epigallocatechin (EGC), (−)-epicatechin (EC), and (−)-epicatechin gallate (ECG), all of which are reported to have positive effects on human health, as well as at the ferric reducing antioxidant power of bud and leaf extracts. The concentration of l-theanine and caffeine decreased as leaf age increased moving from bud to first and then second leaf, while the concentration of the four catechins increased from the bud to first and second leaves. In most cases this increase was generally relatively small but in the case of EGC it was 7 to 10-fold. Certain chemical components of freshly picked, minimally processed and essentially unoxidised tea may potentially be used as markers for age, quality, authenticity and area of growth. 相似文献
20.
This review summarises the information available on the biology, behaviour and economic significance of the common or webbing clothes moth, Tineola bisselliella (Hummel), currently the most important and widespread clothes moth pest throughout the world. These moths can cause the loss of irreplacable material of aesthetic, historic and scientific importance, as well as damaging every-day items such as clothes, furnishings and other materials prepared from animal fur, wool, feathers and hides. Methods for the detection and control of this pest are outlined, with particular emphasis on control strategies that are environmentally sustainable and avoid the use of conventional pesticides and fumigants. Improvements in storage coupled with targeted use of appropriate control measures will help to reduce pest populations. However, the continuing problems with this pest highlight the need for improved methods of detection, prevention and management. 相似文献